Sum of n Terms

Q. If the sum of the series 54, 51, 48, 45.......$T_n$ is 513, then the number of terms are

1. 17
2. 18
3. 20
4. None of these

Q. The value of $\sum _{r=1}^{n}log\left(\frac{a^r}{b^{r-1}}\right)$ is

1. 
2. 
3. 
4. 

Q. If $S_1,S_2,S_3$, ..........$S_m$ are the sums of n terms of m A.P.'s whose first terms are 1, 2, 3, ........ ..... m and common differences are 1, 3, 5, .......... .2m - 1 respectively, then $S_1+S_2+S_3+........S_m=$

1. 
2. 
3. 
4. None of the above

Q.

Find the sum of the first 15 terms of the series 3 + 5 + 7 + 9 +. . . . . . n terms.___

Q.

Harikiran purchased a house in Rs. 15000 and paid Rs. 5000 at once. Rest money he promised to pay in annual instalment of Rs. 1000 with 10% per annum interest. How much money is to be paid by him

1. Rs. 21555

2. Rs. 20475

3. Rs. 20500

4. Rs. 20700

Q.

Find the sum of the first n natural numbers.

1. 

2. 

3. 

4. 

Q.

The sum of (n+1) terms of $\frac{1}{1}+\frac{1}{1+2}+\frac{1}{1+2+3}+..........$ is

1. 

2. 

3. 

4. 

Q.

If sum of $n$ terms of an A.P. is $3n^2+5n$ and $T_m=164$, then the value of $m$ is

1. 26

2. 28

3. 25

4. 27

Q.

$\frac{5+9+13+.......upton.terms}{If7+9+11+.....upto(n+1)terms}=\frac{17}{16}$ then n is equal to

1. 6
2. none of these
3. 7
4. 9

Q. If the sum of the first 2n terms of the A.P. 2, 5, 8, ...., is equal to the sum of the first n terms of the A.P. 57, 59, 61, ...., then n equals

1. 10
2. 12
3. 13
4. 11